The present invention pertains to apparatus related to the repair of live mains lines. More specifically it pertains to variable length repair fitting for use in repairing or reinforcing polyethylene pipelines.
Fluid pipelines were mainly constructed of steel or even cast steel, and were subject to severe corrosion problems as they were buried underground. With the event of plastics, broader usage of different types of elastomeric materials has found favor with the gas pipeline industry. Thus, it is very common for gas pipelines to be constructed entirely out of plastics, especially polyethylene, since such pipelines exhibit excellent corrosion resistance.
However, many of the problems associated with the steel pipelines still occur with the plastic pipelines. For example, uncovering pipelines requires digging the earth around the line, sometimes leading to heavy equipment operators to severely scratch or even rupture the lines. Repairing plastic pipelines requires either spot repairing with traditional clamp and bladder techniques, or by cutting and replacement of the damaged section. It is therefore an object of the present invention to provide an improved method and apparatus for repairing a damaged polyethylene pipeline where the line does not require physical cutting and replacement of the damaged or weakened section.